Aha - here it is on the Aircare website:
House Bill 13-1071 Summary
Changes the definition of a collector’s item to include vehicles that are 32 years old and older.
Requires vehicles model year 1976 and later to comply with emissions testing requirements upon registration and re-registration.
Requires the vehicle owner of a collector’s item to sign an affidavit acknowledging that the vehicle will not be driven on roadways more than 4,500 miles per year.

Who Does the Bill Impact?
Motorists who own a vehicle at least 32 years old are now able to register the vehicle as a collector’s item.
Motorists who own a 1976 and newer model year vehicle that was registered as a collector’s item prior to September 2009. Beginning August 7th, 2013, to re-register a collector’s item that is model year 1976 or later, the owner must have a certificate of emissions compliance.

Benefits to Vehicle Owners [hint: there are no benefits to those who were already grandfathered in and had emissions-exempt status]
Increases the number of vehicles that may qualify as a collector’s item.
Allows vehicles model year 1976 and later, that are registered as a collector’s item, to comply with emissions requirements every five years instead of on an annual or biannual cycle.
Allows vehicles model year 1976 and later, that are registered as a collector’s item, to complete the license plate renewal process every five years instead of annually.